HVAC damper and temperature control

[anderkh]

I have a 4 story townhome with a 4 zone controller and a forced air system. I was looking for a way to sub-zone the 3rd floor (bedroom) zone so that I could control the temps in each room. Unfortunately, the HVAC world seems way behind, and this is a foreign concept to them.

Another option I have is to put in temperature sensors and dampers so that I can manually control this through scripts in Homeseer. Does anyone have any experience with any of this? How can I receive temperatures (without a thermostat) and control dampers with Homeseer?

Thanks,
Ken

[Michael McSharry]

What you want to do is quite doable and it becomes a matter of the degree you want to role your own vs lightening your bank account.

You can do temperature sensing by using thermostats that provide this function or you can separate the temperature, control, and relay logic.

1-Wire technology is the low cost way to obtain temperature measurements and can be used for actuation as well. Several other output interfaces exists that can enable a 24V relay which will do the damper (and optionally furnace) on/off control. In this scenario then your PC contains the control logic.

RCS, and others, make thermostats that can control a damper as well. You can still connect up the computer, but you will need less logic to make it work.

I have computer controlled dampers for fireplace vs furnace heat sources. These are 100% on vs 100% off. I'm not aware of those that can be proportionally controlled and you likely do not need it anyway.

From a safety perspective you need to assure that adequate flow volume occurs. You do not want to block all dampers and still have the furnace trying to push hot air. If you are only going to play with 25% of the system's capacity then this likely will not be a problem.

[anderkh]

Michael,

Thanks for the reply. The way I really wanted to do this is to get an HVAC zone controller, hook up 3 thermostats, and have the zone controller pretend to just be another thermostat. This would work nicely, since the zone controller would only call for heat or A/C when one of the thermostats upstairs is calling, so I'd be sure that the dampers aren't closed. I'm afraid that relying on scripting might be risky. Unfortunately, when I talked to RCS, they said that their controller couldn't be used as a sub-controller to another controller. I would think that just a little bit of wiring would allow this to happen. Do you know of anyplace where I could read up on voltages, etc?

I'll look into the 1-wire technology you mentioned...

Thanks,
Ken